Fallow Crown - Weak to Strong OP MC LitRPG (BOOK 2). Dungeon Chronicles, #2

The seal is gone. The dungeon is awake. And Sevik is inside it. Deeper than any living person has gone in three centuries, the seventh prince descends through a dungeon that is no longer testing him. It is finishing him. Skills flood his body in clusters, each one a fragment of a dead cultivator installed without his consent. His skin turns translucent. His bones glow. The counter in his head climbs toward a number that will erase the last trace of the human body he was born in.
Above him, the palace fractures. A brother breaches the primary seal to harvest the dungeon's power. A councillor uncovers a secret buried in a sixteen-year-old medical file. A woman who held the world together with her bare hands collapses as the formation she gave her life to unravels thread by thread. And Haruke, the brother no one predicted, walks into the Pale Root with his fists and a debt he intends to collect.
At the dungeon's core, a heart beats. Not a crystal. Not a node. A heart grown from six thousand human beings. And at its base, a throne that requires a body made entirely of dungeon architecture to claim. The cost of sitting on it is everything Sevik is. The cost of not sitting on it is everyone above.